Gear-cutting machine.



Y A APPLICATION FILED APR. 1914. I i 1,140,012 r Patented yMay 18, 1,915.

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Nl. TIBBETTS. GEAR CUTTING MACHINE. APPLrcAnoN man APR. i, 1914.

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APPLICATION FILED APR. 7, 1914.

' Patented May 18, 1915.

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entran PATENT GFF 1G13 MILTON TIBBETTS, OF DETROIT, MICHIGAN, ASSGNOR TOv PACKARD MOTOR "CAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

GEAR-cerrarse ernennen.v

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Specification of Letters Patent.

Patented May 1s, 191s.

,flction filed April 7, '1914. Serial No. 830,232.

To aZZ fio/mnt it may concern.'

.lle it known that I, MILTON Tinnn'r'rs, a citizen of the United States, and resident ot' Detroit, lVayne county, State ,of Michigan, have invented certain new and useful lmproveinents in Gear-Cutting Machines, of which the following is a specification.

This invention relates to gear cutting machines and particularly to machines for cutting' gears having curved teeth.

The invention consists broadly of blank holding means in combination with a tool holder adapted to operate the tool to cut intermittent-ly.

ln the embodiment of the invention shown the tool holder is pivotally supported and is oseillated so that the tool passes forth and back across the face of the blank in a curved path., cutting on the forward stroke and beirxo lilted to clear the blank on the return alte. In this construction also the blank tilted intermittently in time Withthe tool operation. i

'The salient object of the invention is to simplify the mechanism of the nulichines of this type and otherwise improve upon their con lotion.

'(,t 'objects of the invention will be 'app-.i from the iollowing description taken in connection with tire drawings, u'lufh torni a part of this invention, and in arbor bearing and spacing head on the line (StG of Fig. 7 Fig. 7 is a section through the spa/Icing head on the line 7-7lol` Figzf; Figi. 8 is a similar section, showingthe working` parts i a diiierent position; Fig. 9 is aI top view of the spacinghead' corresponding; to the sections shown in Figs. 7 and 8; and Fig. l? is an end viewof an arbor flange.

ln the embodiment of the invention shown in the drawings, the frame or bed'of' the Ina chine is indicated at 20., and upon the right end of the frame, as shown in Figs. l and 2 is mounted the means for supporting 'and oper* ating the gear blank. This means intermittently rotates thel blank to coperate With an intermittently operating cutting tool, and rolls the blank on its pitch surface to generate the tooth. It consists principally of a plate 21' mountedl upon a flat upper surface 22 of thetrame, and having a series of circular grooves 23 in which lit the corresponding circular flanges 24 of a securing plate 25, which is fastened to the frame by the screws Q6. The circumference olf the plate 2]. is formed with gear teeth 27, with which meshes al worm 28 driven by a shaft 29,

4whereby the plate 2l is rotated or oscillated about a vertical. axis which passes throurhV the Aapex of the former-cone, hereinafter de scribed.

30 between which is adjustably held a block or bearing 31, as by bolts 32. Thus this bearing is adjustable about the apex of the former-cone for operation upon diferent sized gears or blanks.

The b ank 33 is removably clamped to the arbor 34 whichv operates in the bearing 31, and upon the upper end of the arbor is rotatably mounted the housing 35 of the spacing head, the lower part of this housing comprising the former-cone 36, which is a production of the pitch cone of the blank 33. By'means oi' two steel bands 37, each of which has one end attached to the cone 36 and the other to the body of the machine in such away that one band prevents the slipping of the cone in one direction and the rlhe plate 21 carries tWo uprights 34, this yrolling motion Would'be transmitted td' the' blank 33,'thereby imparting tothe latter thatY motion which is necessary to' cause the tool to generate the proper tooth contour'. As a matter of fact, however, the

holising 35' is only Ainterr'nittently coupled to the' arbor 3t-namelyirduring the forward stroke of the tool. i During the return stroke orm the tool, the blank arbor is rotated in relation to the housing 35 through the' distance, preferably, of one toothY of the blank 'vided with two rollers 41 33. vThis intermittent rotation is accomplished as follows: Within the housing is 'rotatably mounted a worm wheel 38, shown in full lines in Figs. 7 and 8 and in l dotted lines in Fig. 6, Whichworin Wheel is driven by means of a worm 39, operated by a flexible shaft 40, from the tool operating mechanism in timed .relation with the tool,

so that the worm wheel 38 will make oneyhalf of a revolution for every full forward and back movement of the tool.

vThe face of the worm Wheel 38 is prol and 42, which engage with two grooves 43 and 44, planed at right angles to each other, into the face of ajvheel 45. When the Worm wheel 33 is in the position shown'in Fig. 7, the roller 41 enters the groove 43 and imparts to the wheel' 45'a rotary movement of an accelerating nature.

sumed the position shown in F ig. 8, it Will have imparted to .Wheel one-eighthof a until the -tirst semi-revolution of4 'wheel lhas been'completed and the roilers 41 -ing'the forward stroke of revolution, andthe Arate of motion or speed of the wheel 45 will have reached its maximum. As the worm wheel 38 4completes, another oneeighth of a revolution, the movement imparted to .the wheel 45 will be of a retarding nature, and the groove 43 offthe wheel 45 will arrive at the position which the groove 44 assumes in F ig. 7, theroller` atthis time. During of the worm wheei remain stationary the Worm .41 leaving thegroove 38, .the wheel '45.wil1

and 42 have exchanged their positions. The roller 4 2` will then-enter the groove 44, which 'will' then'be inthe `position occupied by theroller 41 and the grooves 43 of Fig. 7, and the.-'o'perationA described 'above will be repeated. Infthi'sway, an intermittent motionl is imparted' to the wheel 45, which is so timed that-.a quarter rotation occurs during the. return stroke .of the cutting tool, while the Wheel 45 will remain at rest dursaid tool. The

g wheel 45is securedto an arbor 46, to which is clamped change-wheel is geared; through. an idler 48pm-the change- Wheel 49, whichis clam ed to an arbor50. This arbor carries aange 51, provided -With arc shaped slots 51, shownin Fig.- 10.

means ofbolts 52 vwhich pass through "551V ably said slots'thell spacing pinion A53 is adjustsecured V.to the 'arbor 50. Thisfpinion engages with the master train of gears just described connects the `After the worm wheel has completed one-eighth of a rotation and as- `47. This Wheel Wheel 54, which isv secured to the blankv arbor 34. Thus. thev .rbevelgearing 141 by the yblank arbor 34., f'rhe trank pin meis-pref' 'so selected that for' For holding the .bunk firmly dering the with the notched anchor wheel 61', which is clamped to the pinion arborl 50. The cam 56 is so' timed that the wheel 61 will be an chored `during the forward stroke ofthe tool and released during the returny stroke, these strokes of thev tool bingfmore fully here-` inafter described. /The tool T is shown in the various figures as o f the usual rack tooth form and it is so mounted and operated that it oscillates or passes intermittently in a curved path crosswise' the .face of the blank. Preferably, operation of the tool is such. that it coperateswith the spacing mechanism of the blank holding and operating means whereby the tool passes across the face of the blank on its ycutting stroke while the blank is held stationary and returns 'to initial position as the blank is rotated one or more tooth spaces. Themeans for supporting und operating the tool comprises a support 13() pivoted on a vertical axis 131 and provided with a tool holder 132 which isl pivoted at 133 to the support 130.' The.' axis 131is an adjustable one and is shown 'asinovable in a substantially horizontal plane land in an arc having-ageneral direction making an angle` to a vertical vplane substantially through "the axis of the gear blank. The bracket 134 in whichfthesupport 130 is supported, is movablyfmounted on the frame 20, and adjustedv by the adjusting screws 135. Screws 136 secure the bracket inv .adjusted position. This construction is showiin section in Fig-.4.1-

It will be understoodiliat the' support tool which it supports 131 thus causing Athe a curved path'in and operates to 'move in the intermittent jvk the areof a: circle, tlie" rudius of 'the are,

depending upon the relative to the lairis '131. 'This distance iS made adjustablelby va'z"}`finp;the` length of the support 130 vby -manipu-latingthe boltv and `slot connection 137, Figs. 1 `and 2, for oscillating embodiment of means comprises ated( by a crank pitt;

the support 130 and ,in the the invention shown,- this rably adjustablev position the tool shown clearly'- in Suitable mea-ns are provided 130- a conn -ingrod 138 operi a 'shaft 1140', f whichshaft vint't11rnis1 operated through. the drivingshaft 142. l

in the s1`ot143of dis-k 144 as shown to vary the strokeA of .the tool or the` degree of oscil- .lationof the support 130.y The, disk 144 is also formed' with gear teeth 1451 meshing with a pinion 146 onv they exible shaft 40,

. the holder.

above described, for driving the latter. As the blank is adapted to be rotated a ,toothvspace during the return or non-cutting stroke of the tool while at the same time it is retained inl the cutting path of the tool, the llatter is raised from cutting position on said return stroke, and suitable means are herein provided for thus raising the tool. The tool is shown as yieldingly held in its normal or cutting position by a springvlt?, and in the form of the invention Ashown in Figs. 2 and 3, the tool holder-132 is adapted to be raised from normal position by means of a push rod148 mounted in suitable lugs 149 and acting upon a pin l5() secured in The push rod 1118 is operated directly by a cam 151 on an arm 152 form ing an extension of the connecting 'rod 138. Thus it will be seen that as the support 130 reaches the forward end of its stroke, the connecting r'od 138 is moved laterally and the cam 151 operates to push the push rod 148 lengthwise and act upon the pin 150 to raise the tool holder 132 vfrom its normal position to such position that the tool will clear the blank upon thc return stroke. The conneet-ing rod 13S again moves laterally at the -end of the return stroke of the support 130 so that the tool holder again assumes normal position for the cutting stroke.A

Another form of tool holder lifting mechanism is illustrated in Fig. 5. rIn this case an arm 153 is directly keyed to the pivot 13- of the tool holder 132, and this arm is acted upon directly by the cam 151 hereinabove, described. This construction gives the same results as that shown in Figs. l, 2 and 3.

,lt will be understood that the invention is not limited to the specific form 4of the machine shown herein, but is capable of modification in various ways Without departing from the scope of the claims.

Having thus described my invention, what I claim and desire to secure by Letters Pat-y ent isz- 1. In a. gear cutting machine, in combination, means for supporting the blank, a tool support, means for oscillating the tool support so as to more the tool in a path concentric to the axis of oscillation to shape the tooth, and means for producing a` relative' movement between the lblank and .tool to generate the tooth.

2. In a gear cutting machine, in combinaltion. means for supporting the blank, a.

pivotallv mounted tool support, means for oscillating' the tool supportv upon and concentricy to its pivot to provide the cutting movements of the tool, and'means for producing a rela tive movement between the 5 ad the tool to generate the tooth.

i a ,ewicutting machine, in combinaior supporting-thc blank, a piv- .supporh and means for oscillating 5. In a gear cutting machine, in combination, means for supporting the blank, a tool support, a tool holder pirated on said support, means for oscillating the tool support so as to move the tool in a path concentric to the 'axis of oscillation to cut the tooth, and means operated by said oscillating means for lifting the tool holder on the return oscillating stroke of the support.

6. In a gear cutting machine, in combination, means for supporting the blank, a tool support, a tool holder pivoted on said support, means for oscillating the tool support so as to move the tool in a path concent-ric to the axis of oscillation to out the tooth, and a finger moved by said oscillating means for lifting the tool holder on the return oscillating stroke of the support.

7. In a `gear cutting machine, in combination, means for supporting the blank, a tool support,l a tool holder pivotcd on said support, meansfor oscillatingr the tool support coniprising an eccentric and connecting rod mechanism, and an extension on said connecting rod for lifting the tool holder on alternate oscillating strokes of the support.

S. In a gear cutting` machine, in combination, means for supportingI and intermittently rotating the blank 'on its axis, a tool support, means for oscillating the tool support so as to more the tool in a path concentric to the axis of oscillation to cut the gear, the oscillations beingin time with the mtern'nttent rotary motion of the blank, and means for producing a relative moreY ment between the blank and the tool to generate 'the tooth.

9. In a gear cutting machine, in combination, means for supporting and intermittently rotating,T the blank on its axis, a pi votally mounted tool support having a tool which moves in a .path concentric to the pivot of the support, means for moving the tool support on its pivot and causing the tool to make intermittent cutting strokes across the face of the blank in ytime With the intern'iittcnt motion ofthe blank, and

Emeans for producing a relative fmovement 'between the blank and the tool to generate the tooth. f

10. In a gear cutting machine, in combi- Sti nation, means for supporting the blank, a

tool support mounted 'to move bodily about cutting strokes of an axis, la tool mounted -on said support, means for moving the tool support about its axis to cause the tool to make intermittent cutting strokes in apath concentricto the 'axis of the support, means? for rotating space after each fof said the tool, `and means'promeans for operatingthe too -sup rt en its vpivot'toj. effect-'the c ut in theblang.o v

In a'gear cutting machine, vilidcombipi'votedtool support and tool thereon 'erv the 'blank a tooth ducing a relative movement betweenthe blank and tool to generate the tooth.`

11.- In a gear cutting machine, in combination, means for supporting the blank, -a tool support mounted yto move bodily about an axis, a tool mounted on-said `support,

means for moving the tool support about its axis to cause the tool to make intermittent cutting strokes in a path concentric to thev axis of the support, means for rotating i the blank intermittently a tooth space at a time without changing the relation of the axis of the blank to the aXis, of the tool support except as tlie'relation of `said axes may be changed by. the. generation of the tooth,' and means producing a relative movement between the blank and tool t0 generate the tooth.

.'12, In a gear cutting machine, in'combination,':1 neans for supporting the blank, av tool support mounted to move bodily about 1an' aXis,-a tool mounted on said support,

meansffor moving thc 'tool' support about its axis to cause the tool to make intermittent cutting vstrokes in a path concentric to the axis of the support, means for rotating thegblankl intermittently a tooth space at a time while retaining the blank in the cutting4 path of the. tool, said rotation of the bla-nk being in timed relation to the movemcnt'f-of the to'ol support, and means pro- ,during ,a relative movement between the- I 40,

blank ,and tool to'generatethe tooth.

13. Inv a gear cutting' machine, 1n combination, means for supporting the blank, a

tool support mounted to move about an axis, atool mounted on Asaid support, means for oscillating thev tool support -to cause the ltool t0 make intermittent cutting strokes in a path concentric to thev axis of the support, means for rotating the blank intermittently a tooth space at' a time while retaining it in the cuttingpath of the tool,

means for lifting the tool on alternate oscillating strokes of the support to clear theA blank, and means for producing a relative movement between the blank and tool to generate the tooth.

v 'pivoted tool support and tool thereon arnation, means for supporting the axis ofthe supgortrsaid sup :oom-- moved by saidoscillating meansv fo'r-liftin lthe su port.

- holder,

l a dev-ice movedv by said In a gear cutting machine, in combi-` nation, means for supporting theblank, a

15.- In a gen1 Guang machine, in cambi.' u

l the blanken oscillatory tool. support an tool thereon arrangfd'- to move in a path-concentric'to vative po- Pivbtirlnd.

prising means for .a justing the'.- sitionpf the' tool and [sup rt' ranged to move in a path concentric tothe axis of they support, .means foroscillating rhevtool support 4to eifect la cut, and n device di n a gear cutting machine, combination, means for supporting-the'blank,1il

the tool 4on the ret-urn oscillating stroke tool support, atool'holdery ypivoted on said- B support, an arm keyedto lthe ypivot ofv said means for oscillating the support so as to move the tool v ina path-concentric to' the axis of oscillation of. -.the support, and o scillatln means for contacting said r'arm and .turning said holder on its pivot.

8 In a gear cuttingmachine, in combi-v 'A nation,

tool support, a tool ho der keyed to ahorimeans vfor supporting the vblank, a A 0 5 zont-alplvot on saidsupport,said'pivothavv ing anarni, means for oscillating th sup-' acranky and connecting rod, and a cam yon said Aconneti'n to operate on said armat teend' o i stroke to turn'the holder'onits ivot `and Y lift the toolon alternate-strokes@ the support. f 19. In a gear cutting machine, in'.r combination,"means for supporting the blank, pivoted tool support and tool thereon arrange to movein a path concentric to the axis of the support, adjusting means for varying the radial position of the tool relatively tothe support pivot, adjusting means for varying the' positionl of the supporty pivot relatively to the blank, and means for moving the tool support'on its pivot to effect the cut in the blank.

Qld/In a gear cutting machine, in combipivoted tool support andtool thereon'al'-, ranged to move ina path concentric tothe axis .of the supporti, adjusting means for varying the radial position of the tool reletively to the supportV pivot, means for ed@ from the axis of the blank, and mbans f rodada ted S nation, means. for supporting the blank, a, l

moving the tool support on its pivot to elf 1 the cut in the blank.

2l. In a gear c utting machine, in '.combination, means'for supporting theV blank, a pivoted tool support and tool thereon arranged to move in a path concentric to the the tool spport on its pivotl to effect the I axis of the support, adjusting means for out in the blank. v

varying the radial position of the tool relal In testimony whereof I affix my signature tively to the support pivot, means for adin presence of two Witnesses.

justing the support pivot in a. substantially horizontal plane and in an are having a gen- MILTON TIBBE'ITSI x; eral direction ,making an angle to a vertical Witnesses: Y l Y plane passingjsubetantially through the axis LEROI J. WmLLAMs,

of the gear blank, and means for moving CLAIR J. COTE. 

